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        <p>Library Version 11.2.5.3</p>
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      <p>The C API for the Berkeley DB Memory Pool subsystem was reworked in the 4.0
release as follows:</p>
      <div class="informaltable">
        <table border="1" width="80%">
          <colgroup>
            <col />
            <col />
          </colgroup>
          <thead>
            <tr>
              <th>Historic functional interface</th>
              <th>Berkeley DB 4.X method</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td>memp_register</td>
              <td>
                <a href="../api_reference/C/mempregister.html" class="olink">DB_ENV-&gt;memp_register()</a>
              </td>
            </tr>
            <tr>
              <td>memp_stat</td>
              <td>
                <a href="../api_reference/C/mempstat.html" class="olink">DB_ENV-&gt;memp_stat()</a>
              </td>
            </tr>
            <tr>
              <td>memp_sync</td>
              <td>
                <a href="../api_reference/C/mempsync.html" class="olink">DB_ENV-&gt;memp_sync()</a>
              </td>
            </tr>
            <tr>
              <td>memp_trickle</td>
              <td>
                <a href="../api_reference/C/memptrickle.html" class="olink">DB_ENV-&gt;memp_trickle()</a>
              </td>
            </tr>
            <tr>
              <td>memp_fopen</td>
              <td>
                <a href="../api_reference/C/mempfcreate.html" class="olink">DB_ENV-&gt;memp_fcreate()</a>
              </td>
            </tr>
            <tr>
              <td>DB_MPOOL_FINFO: ftype</td>
              <td>
                <a href="../api_reference/C/mempset_ftype.html" class="olink">DB_MPOOLFILE-&gt;set_ftype()</a>
              </td>
            </tr>
            <tr>
              <td>DB_MPOOL_FINFO: pgcookie</td>
              <td>
                <a href="../api_reference/C/mempset_pgcookie.html" class="olink">DB_MPOOLFILE-&gt;set_pgcookie()</a>
              </td>
            </tr>
            <tr>
              <td>DB_MPOOL_FINFO: fileid</td>
              <td>
                <a href="../api_reference/C/mempset_fileid.html" class="olink">DB_MPOOLFILE-&gt;set_fileid()</a>
              </td>
            </tr>
            <tr>
              <td>DB_MPOOL_FINFO: lsn_offset</td>
              <td>
                <a href="../api_reference/C/mempset_lsn_offset.html" class="olink">DB_MPOOLFILE-&gt;set_lsn_offset()</a>
              </td>
            </tr>
            <tr>
              <td>DB_MPOOL_FINFO: clear_len</td>
              <td>
                <a href="../api_reference/C/mempset_clear_len.html" class="olink">DB_MPOOLFILE-&gt;set_clear_len()</a>
              </td>
            </tr>
            <tr>
              <td>memp_fopen</td>
              <td>
                <a href="../api_reference/C/mempfopen.html" class="olink">DB_MPOOLFILE-&gt;open()</a>
              </td>
            </tr>
            <tr>
              <td>memp_fclose</td>
              <td>
                <a href="../api_reference/C/mempfclose.html" class="olink">DB_MPOOLFILE-&gt;close()</a>
              </td>
            </tr>
            <tr>
              <td>memp_fput</td>
              <td>
                <a href="../api_reference/C/mempput.html" class="olink">DB_MPOOLFILE-&gt;put()</a>
              </td>
            </tr>
            <tr>
              <td>memp_fset</td>
              <td>DB_MPOOLFILE-&gt;set</td>
            </tr>
            <tr>
              <td>memp_fsync</td>
              <td>
                <a href="../api_reference/C/mempfsync.html" class="olink">DB_MPOOLFILE-&gt;sync()</a>
              </td>
            </tr>
          </tbody>
        </table>
      </div>
      <p>Applications calling any of the memp_register, memp_stat, memp_sync or
memp_trickle functions should update those calls to use the enclosing
<a href="../api_reference/C/env.html" class="olink">DB_ENV class</a> handle's method (easily done as the first argument to the
existing call is the correct <a href="../api_reference/C/env.html" class="olink">DB_ENV class</a> handle).</p>
      <p>In addition, the <a href="../api_reference/C/mempstat.html" class="olink">DB_ENV-&gt;memp_stat()</a> call has been changed in the 4.0
release to take a flags argument.  To leave their historic behavior
unchanged, applications should add a final argument of 0 to any calls
made to <a href="../api_reference/C/mempstat.html" class="olink">DB_ENV-&gt;memp_stat()</a>.</p>
      <p>Applications calling the memp_fopen function should update those calls
as follows: First, acquire a <a href="../api_reference/C/memp.html" class="olink">Cache chapter</a> handle using the
<a href="../api_reference/C/mempfcreate.html" class="olink">DB_ENV-&gt;memp_fcreate()</a> method.  Second, if the DB_MPOOL_FINFO structure
reference passed to the memp_fopen function was non-NULL, call the
<a href="../api_reference/C/memp.html" class="olink">Cache chapter</a> method corresponding to each initialized field in
the DB_MPOOL_FINFO structure.  Third, call the <a href="../api_reference/C/mempfopen.html" class="olink">DB_MPOOLFILE-&gt;open()</a> method
method to open the underlying file.  If the <a href="../api_reference/C/mempfopen.html" class="olink">DB_MPOOLFILE-&gt;open()</a> method call
fails, then <a href="../api_reference/C/mempfclose.html" class="olink">DB_MPOOLFILE-&gt;close()</a> method must be called to destroy the allocated
handle.</p>
      <p>Applications calling the memp_fopen, memp_fclose, memp_fput, memp_fset,
or memp_fsync functions should update those calls to use the enclosing
<a href="../api_reference/C/memp.html" class="olink">Cache chapter</a> handle's method.  Again, this is easily done as the
first argument to the existing call is the correct <a href="../api_reference/C/memp.html" class="olink">Cache chapter</a>
handle.  With one exception, the calling conventions of the old and new
interfaces are identical; the one exception is the <a href="../api_reference/C/mempfclose.html" class="olink">DB_MPOOLFILE-&gt;close()</a> method,
which requires an additional flag parameter that should be set to 0.</p>
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